1. Field of the Invention
This invention relates to a vehicle lamp having a plurality of lamp units for radiating beams in different directions.
2. Description of the Related Art
A conventional vehicle lamp has a lamp unit such as a headlamp (hereinafter referred to as xe2x80x9cfirst lamp unitxe2x80x9d) for radiating a beam toward a road surface ahead of a vehicle, as well as a lamp unit such as a bending lamp(hereinafter referred to as xe2x80x9csecond lamp unitxe2x80x9d) for radiating a beam toward a road surface obliquely ahead of the vehicle.
Generally, the second lamp unit is constructed to reflect light from a light source in a diffusive/deflective manner using a reflector.
The first lamp unit is configured to illuminate the road far ahead of the vehicle, while the second lamp unit is configured to illuminate the road close to the vehicle. Consequently, the second lamp unit is set to radiate in a more downward direction than the first lamp unit.
However, if the second lamp unit is set to a downward direction with a relatively large angle, the reflected light from the reflector radiates on a lower wall surface of this reflector and a lower wall surface of the lamp body. Therefore, the radiating beam, directed toward a zone of the road near and ahead of the vehicle, cannot be sufficiently attained.
The present invention provides a vehicle lamp in which a first lamp unit for radiating a beam toward a road surface ahead of a vehicle, as well as a second lamp unit for radiating a beam toward a road surface obliquely ahead of the vehicle, is received within a lamp chamber. The radiating beam from the second lamp unit, which is directed toward a zone of the road near and ahead of the vehicle, can be sufficiently attained.
In the present invention, the above object has been achieved by providing suitable arrangements of, for example, the location of a second lamp unit.
Further, according to the present invention, a first lamp unit for radiating a beam toward a road surface ahead of a vehicle, as well as a second lamp unit for radiating a beam toward a road surface obliquely ahead of the vehicle, is received within a lamp chamber formed by a lamp body and a light-transmitting cover.
The two lamp units are arranged in two vertically-spaced stages in such a manner that the second lamp unit is disposed in an upper position. The second lamp unit includes a light source, and a reflector for reflecting light from the light source in a diffusive/deflective manner. The second lamp unit is so constructed that at least part of the reflected light from the reflector passes through the light-transmitting portion of the cover disposed forwardly of the first lamp unit.
With respect to the lamp units of the above xe2x80x9cvehicle lamp,xe2x80x9d only the first and second lamp units can be received within the lamp chamber, or other lamp unit(s) in addition to the first and second lamp units can be received within the lamp chamber.
The specific construction of xe2x80x9cthe first lamp unitxe2x80x9d is not particularly limited, and the first lamp unit can be formed, for example, as a lamp unit (so-called paraboloid-type lamp unit), including a light source, and a reflector for reflecting light from this light source in a diffusive/deflective manner or as a lamp unit (so-called projector-type lamp unit) including a light source, a reflector for reflecting light from this light source in a condensing manner, and a projection lens disposed forwardly of this reflector.
The xe2x80x9csecond lamp unitxe2x80x9d can be configured to light only when the first lamp unit is lit, or can be configured to light independently of the first lamp unit, or can be configured to light only in a predetermined condition such as just before and/or during turns, or can be configured to light always.
The phrase xe2x80x9cto reflect the light in a diffusive/deflective mannerxe2x80x9d means reflecting light in a diffusive manner, a deflective manner, or a deflective and diffusive manner.
In the above embodiment, the first lamp unit for radiating a beam toward a road surface ahead of the vehicle, as well as the second lamp unit for radiating a beam toward a road surface obliquely ahead of the vehicle, is received within the lamp chamber formed by the lamp body and the light-transmitting cover. However, the two lamp units are arranged in two vertically-spaced stages so that that the second lamp unit is disposed in the upper position. The second lamp unit is configured so that at least part of the reflected light from the reflector passes through that portion of the light-transmitting cover disposed forwardly of the first lamp unit. Therefore, the direction of radiation of the beam from the second lamp unit can be set to a considerable downward direction.
Therefore, in the vehicle lamp of the present invention in which the first lamp unit for radiating a beam toward a road surface ahead of the vehicle, as well as the second lamp unit for radiating a beam toward a road surface obliquely ahead of the vehicle, is received within the lamp chamber, the radiating beam from the second lamp unit, which is directed toward a zone of the road near and ahead of the vehicle, can be sufficiently attained.
In the above embodiment, where the first lamp unit includes the light source, and the reflector for reflecting light from this light source in a diffusive/deflective manner, the construction of the vehicle lamp can be simplified by integrally forming the reflectors of the two lamp units.
In the above embodiment, where the optical axis of the second lamp unit is inclined outwardly in the direction of the width of the vehicle at a predetermined angle relative to a forward-rearward direction of the vehicle, the following operational effects can be obtained.
The second lamp unit is configured to radiate a beam toward a road surface obliquely ahead of the vehicle, and where this beam radiation is effected only by the diffusive/deflective control of the reflector, it is necessary to set the angle of horizontal deflection of the reflected light to a large value. Therefore, unevenness can develop in the luminous distribution pattern formed by the beam radiated toward the road surface obliquely ahead of the vehicle. Furthermore, the efficiency of the vehicle lamp may be degraded.
In this respect, where the optical axis of the second lamp unit is inclined outwardly in the direction of the width of the vehicle at the predetermined angle relative to the forward-rearward direction of the vehicle, it is not necessary to set the angle of horizontal deflection of the reflected light from the reflector to a large value. Therefore, unevenness is less likely to develop in the luminous distribution pattern formed by the beam radiated toward the road surface obliquely ahead of the vehicle. Further, the efficiency of the vehicle lamp can be enhanced.
In many cases, the vehicle lamp is mounted at a corner portion of a vehicle body, and an upper portion of this corner portion of the vehicle body is, in many cases, formed into a generally-rounded, curved shape. Where the optical axis of the second lamp unit is inclined outwardly in the direction of the width of the vehicle at the predetermined angle relative to the forward-rearward direction of the vehicle, the second lamp unit can be easily arranged in conformity with the curved shape of the corner portion of the vehicle body.
Here, although xe2x80x9cthe predetermined anglexe2x80x9d is not particularly limited to any specific value, it can be set to the range of between 10xc2x0 and 60xc2x0, preferably to the range of between 20xc2x0 and 50xc2x0, and more preferably to the range of between 30xc2x0 and 40xc2x0.
The specific construction of the above xe2x80x9csecond lamp unitxe2x80x9d is not particularly limited, but where the second lamp unit is formed as a bending lamp for illuminating a road surface ahead in a turning direction when the vehicle turns or is about to turn (blinkers on), a zone of the road near and ahead in the turning direction can be sufficiently illuminated by the beam from the second lamp unit. Thus, the visibility for this near zone can be enhanced, thereby promoting safety even just before and during turns.